Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Introduction to Physics
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Introduction to Physics
∫ dx 2ax - x^2 = a^n ^ -1 ((x)/(a) -1) . Determine the value of n ....
.
Determine the value of .
You may use dimensional analysis to solve the problem.$$
Determine the value of .
You may use dimensional analysis to solve the problem.$$
Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
Let the dimension of be .
The dimension of is .
For the term to be dimensionally consistent, the dimension of must be .
The dimension of the denominator is .
Therefore, the dimension of the left-hand side is .
On the right-hand side, the argument of the inverse sine function, , is dimensionless. The function yields an angle, which is also dimensionless.
Thus, the dimension of the right-hand side is .
Equating the dimensions of both sides, we get , which implies .
Alternatively, evaluating the integral directly:
Using the standard formula \left(\dfrac{x}{a}\right), we get:
\int \dfrac{dx}{\sqrt{a^2 - (x - a)^2}} = \sin^{-1} \left(\dfrac{x - a}{a}\right) = \sin^{-1}\left(\dfrac{x}{a} - 1\right)a^n \sin^{-1} \left(\dfrac{x}{a} -1\right)a^n = 1n = 0
The dimension of is .
For the term to be dimensionally consistent, the dimension of must be .
The dimension of the denominator is .
Therefore, the dimension of the left-hand side is .
On the right-hand side, the argument of the inverse sine function, , is dimensionless. The function yields an angle, which is also dimensionless.
Thus, the dimension of the right-hand side is .
Equating the dimensions of both sides, we get , which implies .
Alternatively, evaluating the integral directly:
Using the standard formula \left(\dfrac{x}{a}\right), we get:
\int \dfrac{dx}{\sqrt{a^2 - (x - a)^2}} = \sin^{-1} \left(\dfrac{x - a}{a}\right) = \sin^{-1}\left(\dfrac{x}{a} - 1\right)a^n \sin^{-1} \left(\dfrac{x}{a} -1\right)a^n = 1n = 0